Vacuum-tube circuits



H. D.'ARNOLD. VACUUM TUBE CIRCUITS. APPLICATION FILED NOV. 11, I920.

I j ifi' //7ve/77or: fiaro/d .0. A rho/a Patented Jan. 17, 1922.

UNITED STATES PATENT OFFICE,

HAROLD D. ARNOLD, OF MAPL EWOOD, NEW JERSEY, ASSIGNOR TO WESTERN ELEC TRIO GOMPANYyINCOBPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

vacuum-runs cracurrs.

Original application filed September 3,1915, Serial No, 48,873. Divided and-this application filed Nojvembcr 11, 1920. Serial No. 423,259.

To all whom it may concern:

Be it known that I, HAROLD DE F. ARNOLD, a citizen of the United States residing at MapIlewood, in the county of lEssex, tate of ew Jersey, have invented certain new and useful Improvements in Vacuum-Tube Circuits, of which the following is a full,

an improved circuit connection between vacuum tubes whereby fluctuations of cur-' rent in the output circuit of one vacuum the flow of direct current, and a direct contube may be impressed on the input circuit of another vacuum tube.

In accordance with this invention, the output circuit of a vacuum tube is provided with a path for direct current comprising an impedance, preferably a resistance and the input circuit of the succeeding tube is connected across a portion of the dlrect current path containing said impedance. condenser is placed between the direct current circuit and the second tubeto prevent nection is also made between the input elecfiled September 3,

trodes of the second tube so that a normal potential difference may be applied therebetween. I

This type of connection is also useful for connecting described, and shown in the accompanyingdrawing, in which the figure represents,

schematically, a circuit embodying the invention.

The subject matter of this ap ilzication is divided out of application Seria 0. 48,872; 1915, for radlo commumcation.-

, Reference numerals are used'in -Rp 'l tio corresponding to those used in the api e at'ed with 0011 36 may be connected to plication above referred to.

This application is a continuation in art circuits of various kinds either with the input terminals or the output terminals of a vacuum tube.

July 30, 1918, now Patent No. 1,329,283, dated January 27, 1920.

C011 13,-which may be connected to any suitable circuit upon which electric impulses may be impressed is inductively connected with the tuned ,circuit comprising coil 19 and condenser 20. Across the terminals of condenser 20, is connected the input circuit of a detecting device which comprises vacuum tube 21, condenser 22 and resistance 23. For the detection of modulated high frequency signals the purpose of thecombination of the condenser and high resistance in connection with vacuum tube 21 1s as follows-when a positive charge, for

example, is forced upon the grid 9 of element 21, this charge is neutralized by electrons from the filament 8. Then, when a negative charge is forced upon the grid by the incoming wave, this charge adds to that already present and produces a still larger negative charge upon the grid, since the negative charge cannot be neutralized bythe electron stream. The condenser, therefore, A aids 1n decreasing the average current 1n the output circuit. The grid must, however,

'be conductively connected to the incoming circuit, otherwise the accumulated negative charge would remain and. prevent further operation. To provide for this, a high resistance leakage path 23 .is shunted around the condenser 22 to allow a leak, slow compared with the eriod of high frequency currents, but still rapid enough to permit considerable leakage in a time comparable with a period of telephonic waves.

The output circuit of this vacuum tube is supplied with current by battery 27 coming t rough choke coil 28 and resistance 25, to the anodelO condenser 24'serving'as a high frequency shunt and condenser 26 to cuit. The amplifier tube 3f has aibattery 30 in series with its id with resistance 29 across its input circuit. The output circuit I limit the direct current to the detector cir amplifis m t I said input electrodes.

While a circuit has been shown which is especially adapted for the detection and amplification of modulated high frequency currents, it is obvious that the features of the circuit relating to the object of this invention areadapted for use in repeating electrical impulses of other forms.

What is claimed is:

1. In combination, a vacuum tube having output electrodes, a path com rising a source of direct current and an impedance connected to said-electrodes, a second path comprising a condenser and the input electrodes of a second vacuum tube connected across a portion of said first path containing said impedance, and means for applying a steady difference of potential between 2. In combination, a vacuum tube having output electrodes, a path comprising a source of direct current and' a resistance connected to said electrodes, and a second path comprising a condenser and the input electrodes of a second vacuum tube connected across a portion of said first path containing said resistance, and means for applying a steady difference of potential between said input electrodes.

3. In combination, a vacuum tube having output electrodes, a path comprising a source of direct current and an impedance connected to said electrodes, a second path comprising a condenser and the input elec-' trodes of a second vacuum tube connected across a portion of said first path containing said impedance, and a conductive path between the input electrodes of said second tube.

4. In combination, a vacuum tube having output electrodes, a path comprising a source of direct current and a resistance connected .to said electrodes, a second path comprising a condenser and the input electrodes of a second vacuum tube connected across a portion -of said first path containing said resistance, and a conductive path.

bcltpveen the input electrodes of said second tu e.

5. In combination, a vacuum tube having output electrodes, a path comprising a source of direct current and a resistance connected to said electrodes, a second path comprising a condenser and the input electrodes of a second vacuum tube connected across that portion of said first path comprising said resistance and said source of direct potential, and a conductive path be- V the other of said tubes, said circuit com-' tween the input electrodes of said vacuum tube.

6. In combination, two vacuum tubes. a circuit connecting the output electrodes of one of said tubes to the input electrodes of prising a series condenser and a shunt impedance at each side of said condenser.

and a path of low 7. In combination, two vacuum tubes, a circuit connecting the output electrodes of one of said tubes to the input electrodes of the other of said tubes,,said circuit comprising a series condenser and a shunt path at each side of said condenser," each of said paths comprising a reslstance.

8. In;- combination a circuit comprising a tions on said electrodes, said connectionscomprising a series condenser.

10. In combination, a circuit comprising a resistance and means for producing potential variations across said resistance, a vacuum tube having input electrodes, connections for impressing said variations on said electrodes, said connections comprising a series condenser, and a resistance shunt for said input electrodes.

11. In combination, a circuit .for the reception of modulatedhigh frequency cur-' rents. a vacuum tube for detecting and amplifying said currents, said vacuum tube havlng an impedance in its. output circuit,

and a circuit connected substantially in parallel with said impedance for impressing variations in the output circuit on another amplifier, said second circuit comprising a series condenser.

'12. In combination, a circuit for the reception of modulated high frequency currents, a vacuum tube for detecting and amplifying said currents, said vacuum tube having an impedance in its output circuit, a circuit connected substantially in parallel with said impedance for impressing variations in the output circuit on another amplifier, said second circuit comprising a series condenser, and a shunt conductance.

13. A detector and amplifier of high frequency currents having in its output circuit a source of direct current, an inductance and a resistance in series, an amplifier having its input circuit in parallel with said series circult, and a path of low impedance having 14. A detector and amplifier of high frequency currents havingin its output circuit a source of current and an inductance, a translating device having an input circuit connected in parallel to a portion of said output circuit containing said inductance,

impedance to high he quency current connected in parallel to a and a work circuit, said second path being portion of said output circuit containing in parallel to a portion of said first path 10 said inductance. containing said impedance.

15. In combination, a vacuum tube having In witness whereof, I hereunto subscribe output electrodes, a path for direct current my name, this 5th day of November, A. D. comprising said output electrodes, a source 1920. of current and an impedance, and a path for alternating currents comprising a condenser HAROLD D. ARNOLD. 

